I have only ever deployed web parts from development by clicking F5. Now, I know I have to have a manifest file, feature file, etc and it all goes into a wsp file. I understand the wsp file is what gets added to Central Admin.
So my problem is this. I have found lots of sites that show how to use WSP Builder, but they don't seem to show how/where I add my web part to the WSP Builder project. My understanding is that somehow I should be able to use WSP Builder to create a wsp file containing my already-developed web part.
There are only two approaches that I see would work.
I create a WSPBuilder project (like all the how-tos on WSPBuilder show), then I assume I would somehow add my web part to that project - although I don't know how.
In my web part project, create WSPBuilder -> Build WSP. I have done this, and when I run stsadm on the resulting wsp file, I get it in Central Admin, but its not added to my Site Collection Features or my Web Part Gallery.
Can someone please explain this to me like I am a 6 year old? If you point me to another site, there is a good chance I have already seen it, so then I would ask you point me to the specific lines that tell me how to get my already existing web part packaged into the wsp.